This invention relates generally to sprinkler devices and, more specifically, to rotary sprinkler devices of the pop-up type. These are devices which are designed for in-ground installation typically used in automatic sprinkler systems, and where the sprinkler head moves from a below ground inoperative position, to an above ground operative position in response to the flow of water under pressure.
Rotary sprinklers of the pop-up type are well represented in the patent literature. See for example, U.S. Pat. Nos. 32,386; 3,713,584; 3,724,757; and 3,921,910. In addition, U.S. Pat. No. 3,934,820 describes a rotary pop-up sprinkler which utilizes a gear train to reduce the rotational speed of the rotary nozzle. Reversible, turbine driven sprinkler heads are described in U.S. Pat. Nos. 4,201,344 and 4,624,412. A two-stage pop-up rotary sprinkler is disclosed in U.S. Pat. No. 4,796,809, while the utilization of a viscous brake for controlling nozzle rotation in a pop-up sprinkler is described in U.S. Pat. No. 4,815,662.
Commonly owned prior U.S. Patent Nos. 4,660,766 and 4,796,811 disclose rotary sprinklers of a non pop-up type which incorporate viscous speed reducing assemblies for slowing the rotational speed of a rotary distributor driven by a water stream discharged from an otherwise stationary nozzle.
The present invention relates to a stream propelled rotary sprinkler of the pop-up type which is characterized by improved performance, simplified construction and lower cost than prior sprinklers of the same or similar type, as explained in greater detail below.
In a preferred embodiment, the device includes an outer housing or stem designed for in-ground installation, and first and second inner housings or stems telescopically mounted within the outer housing. Upon commencement of flow of water under pressure into the sprinkler device, the first and second inner housings are extended to an above ground position, and the first inner housing is then further extended relative to the second inner housing to a fully extended, operative position. The first and second inner housings are normally spring biased to the below ground, inoperative position so that, upon cessation of the supply of water under pressure, the first and second inner housings will return automatically to a below ground, inoperative position within the outer housing.
It will be appreciated that, if desired, the second (or intermediate) housing may be omitted so that only a single telescoping arrangement is employed. In this event, of course, the first inner housing would be lengthened so that the desired extension will occur.
The first inner housing is provided with a rotatable nozzle disk formed with at least one discharge orifice for discharging the stream of water under pressure. The discharge orifice preferably is in the form of an arcuate slot, extending slightly more than 180.degree. about the disk center, which coincides with the longitudinal axis of each of the three housings.
The first inner housing is also provided with an outlet end including a second arcuate slot through which water is discharged from the interior of the sprinkler. In a preferred embodiment, this second slot also extends slightly more than 180.degree., and preferably about 200.degree., about the longitudinal axis of the inner housing. In addition, the width of this second slot is greater than the width of the first slot formed in the nozzle disk. The nozzle disk is located adjacent and downstream of the outlet end of the first inner housing so that the first and second slots lie in back-to-back relationship. Moreover, the first and second slots are radially located such that the nozzle slot is rotatable into and out of alignment with the outlet end slot, and within the width of the outlet end slot. Thus, it will be appreciated that the nozzle slot serves to open any increment or substantially all of the outlet end slot so as to permit virtually infinite arcuate sprinkling patterns from between about 0.degree. and about 180.degree. degrees.
Water under pressure issuing from the nozzle disk impinges on a rotary distributor which, in turn, redirects and distributes the water over a predetermined area as will be described in greater detail further herein.
In an alternative arrangement, the nozzle disk can be provided with a plurality of apertures arranged in a circular pattern and selectively movable into the outlet end slot area by rotation of the nozzle disk. Variations in the shape, number and spacing of such apertures are within the scope of this invention.
In another aspect of the present invention, the rotary distributor itself encloses a "rotor motor", or viscous speed reducing assembly, for slowing the rotational speed of the distributor which would otherwise rotate at high speed (e.g., about 1800 rpm or more) as a result of the direct impingement of the pressurized stream on slightly radially offset grooves formed in a lower face of the distributor.
The viscous brake assembly is generally similar to that disclosed in commonly owned U.S. Pat. Nos. 4,660,766 and 4,796,811, and recently filed copending application Ser. No. 07,390,286, filed Aug. 7, 1989, with the exception that in the present invention, the shaft and stator member are fixed against rotation, and the stator is enclosed within the rotary distributor.
The combined distributor and speed reducing or brake assembly includes a shaft, one end of which is fixed, i.e., non-rotatably mounted, within the first inner housing, and the other end of which supports the distributor for rotation relative to the fixed shaft, downstream of the nozzle disk discharge orifice. A stator member or drum is mounted on the shaft within a sealed chamber formed by the distributor, and the remaining space in the chamber is filled with a viscous fluid.
The brake device operates on a viscous shear principle whereby viscous liquid between the stator and rotary distributor is caused to shear as the distributor rotates in close relationship to the stationary stator member in the hollow distributor.
The brake assembly is effective to reduce the rotational speed of the distributor from an unbraked speed of about 1800 rpm or more, for a given typical pressure level, to a desired speed of from about 1/4 to 12 rpm at the same pressure. Such speed reduction maximizes the "throw" of the water, while minimizing the well known and undesirable "horse tail" effect which is otherwise experienced at high rotational speeds.
The lower radial face of the rotary distributor in accordance with an exemplary embodiment of the invention is provided with a plurality of radially outwardly and upwardly extending grooves that are slightly radially offset, so that when the stream of water impinges on the grooves, rotary motion is imparted to the distributor. This aspect of the invention is similar to that described in the above-identified copending application.
It will be appreciated that the viscous brake assembly and discharge outlet arrangement of the present invention have many advantages over sprinkler constructions in the prior art. For example, the isolation of the brake assembly away from the sprinkler housing eliminates any need for dynamic shaft seals otherwise required to prevent pressurized water from entering the viscous brake assembly housing. Any water that does contact the shaft externally of the housing has already been discharged from the nozzle disk into atmospheric space, and is at minimal or at least substantially reduced pressure.
At the same time, the adjustable nozzle disk may be rotated manually to create an arcuate discharge slot of from anywhere from close to 0.degree. degrees to about 180.degree. degrees, thereby substantially eliminating the need for maintaining a large number of differently configured nozzle disks.
Thus, in one aspect, the present invention relates to a pop-up, rotating stream sprinkler device comprising:
an outer housing having a first longitudinal axis, and an inlet end adapted for connection to a source of liquid under pressure;
a first inner housing telescopically mounted within the outer housing for movement between retracted and extended positions, and having a second longitudinal axis coincident with the first longitudinal axis, and an outlet end adapted to discharge to atmosphere a stream of liquid under pressure;
a non-rotatable shaft, one end of the shaft supporting a substantially hollow rotary distributor for rotation thereon downstream of the outlet end, and the other end of the shaft fixedly mounted in the first inner housing, and wherein the distributor encloses a brake assembly for retarding rotation of the distributor.
In another aspect, the present invention is directed to a rotary distributor for use with a stream propelled sprinkler, the distributor comprising:
a shaft;
a substantially hollow body portion mounted for rotation on one end of the shaft, the substantially hollow body portion including a brake chamber;
a stator member fixedly secured to the one end of the shaft and located within the brake chamber; and
a viscous fluid within the chamber for effecting braking action on the distributor upon relative rotation between the distributor and the stator member.
It will be understood that the above described rotary distributor may be used in pop-up as well as non pop-up sprinkler devices.
It will thus be appreciated that the sprinkler device as disclosed herein provides a simplified construction which improves performance by maximizing the throw of the water stream via a simple but effective viscous brake assembly, while reducing cost and increasing durability by eliminating the need for pressurized dynamic shaft seals and other drive components typically utilized in such sprinklers, and by providing a virtually infinitely adjustable nozzle arrangement for creating desired arcuate spray patterns.
Other objects and advantages of the present invention will become apparent from the detailed description of the invention which follows.